Steering mechanism for traction-engines, &amp;c.



B. HOLT.

STEERING MECHANISM FOR TRACTION ENGINES, 6w.

APPLIGATION FILED JUNE 26, 1911.

1,1 1 1,961 Patented Sept. 29, 1914.

3 SHEETSSHEET 1.

wagea M14 B. HOLT. STEERING MECHANISM FOR TRACTION ENGINES, 6w.

APPLICATION FILED JUNE 26.1911.

Patented Sept. 29, 1914. 4 s SEEETSSHEET 2.

g LK I B. HOLT.

STEERING MECHANISM FOR TRACTION ENGINES, &0. APPLICATION FILED JUNE26,1911.

Patented Sept. 29, 1914.

3 SHEETSSHEET 3.

BENJAMIN HOLT, or STOCKTON, CALIFORNIA.

STEERING MECHANISM FOR TRACTION-ENGINES, 8w.

inear.

Specification of Letters Patent.

Application filed June 26, 1911.

Patented Sept. 29, 1914;.

Serial No. 635,309.

To all whom it may concern:

Be'it known that I, BENJAMIN HOLT, a citizen of the United States,residing at Stockton, in the county of San Joaquin and State ofCalifornia, have invented new and useful Improvements in SteeringMechanism for Traction-Engines, &c., of. which the following is aspecification.

This invention relates to steering wheels and-their operating means,which wheels are for use with traction engines and other heavy roadvehicles.

The objects and advantages of the invention will be apparenthereinafter.

The invention consists of the parts and the combination and constructionof parts as hereinafter more fully described and claimed, havingreference to the accompanying drawings, in whicl Figure 1 is a sideelevation of a traction engine partly broken away, showing theapplication of my invention. Fig. 2 is a plan view of the steeringwheel. Fig. 3 is a side elevation of same partly broken away.

.Vhile I have shown the invention as applied-especially to a tractionengine of the caterpillar type, it will be manifest thatthe invention isapplicable to other types of traction engines, as well as combinedharvesters, auto trucks, and other heavy vehicles.

A represents the vehicle frame, here shown as comprising two main sillsor I-beams, suitably connected and braced, supported at one end upon thetractors 3, and at the front end by the steering wheel 4. v

The present invention pertains specially to the mounting of the frontsteering wheel 4 and the means for manipulatingit so as to direct thetravel of the vehicle. This wheel 4 has the boxes 5 in which the axle ofthe wheel turns, mounted in vertical guides 6 of the truss-form sidechords 7; there-being a pair of these chords 7, oneon each side of thewheel, and fixed in a turntablering 8, which supports the front end ofthe vehicle frame; the wheel being disposed diametrally of the turntablering 8. The ring 8 is contained within a circular guide 9 carriedbetween the front ends of the sills A, and rigidly secured thereto; thiscircular' guide 9 having an inwardly projecting strong annular trackflange 10, against the underside of which, rollers 11 are adapted tobear;

' these rollers 11 being turnable on horizontal pins 12, carried by apart or parts 13, which latter are integral with, or constructed as afixed part of, the turntable ring 8. The rollers 11 thus provide ananti-friction bearing to support the weight of the vehicle, and

in order to facilitate the easy turning of the wheel and turntablecertain horizontal antifriction rollers 14 may be disposed around theperiphery of the guide 9 and adapted to bear against the outersurface ofthe turntable ring 8. These rollers 14 turn on vertical pivots mountedin suitable casings 15, which casings are bolted to the ring guide 9 andproject through slots in the latter to bring them into tangentialrelationship to form anti-friction side supports with the ring 8.

the weight of the vehicle supported by means of the track 10 running onthe rollers 11; and any shock due to the meeting of the wheel 4 with anobstacle being absorbed by the springs 16.

In order to steer this wheel handily from any suitable point on thevehicle there is provided the following means: Carried by and arrangedon one side of the turntable 1 ring 8 is a segmental rack 18, which isengaged by a pinion 19 mounted on the vertical shaft 20, which isjournaled on the annular guide 9. The upper end of the shaft 20 carriesa Worm gear 21, engaged by a worm 22 on the steering rod 28, whichlatter runs back to a suitable point on the vehicle and is provided witha hand-wheel 24 wherewith the operator may guide the movements of thevehicle. The worm and gear may be suitably incased as shown at 25. Thesteering rod is preferably made readily detachable from the worm shaft,as shown at 26 the two being held together by a clamp lug 27. Removingthe clamp lug 27 by taking out a bolt 28, permits the steering rod 23 tobe through the rod 23, the Worm 22, gear 21 and shaft 20 and gear 19 tothe rack segment 18 on the turntable ring 8. This form of steeringmechanism has been put to exten sive practical use in connection withheavy vehicles of this sort; these vehicles often weighing many tens. Bythe means here employed there is practically no lost motion and theheaviest machine can be readily turned by an operator with a minimumexpenditure of strength.

I By the means employed for supporting the annular guide 9 and track 10on the turntable ring 8 and arranging the rack and pinion in the mannershown, the entire wheel with its turntable which collectively constitutea steering truck, are readily removed from the vehicle by removing clips29 and lifting up the front end of the vehicle frame; the entire truckthereby being withdrawn from any connection with the frame. Clips 29 areattached to the turntable in line parallel with the axis of the steeringwheel, the upper end overhanging the top of the track flange.

An important practical feature of this invention is making the wormgearing selflocking by setting the axis of the steering worm 522 obliqueto the axis of the vertical gear 21; being the use of a skew gearinginstead of the true worm gearing.

Referring to Fig. 3 it will be noted that the plane of the teeth on theworm gear 22 are in approximate parallelism with the axis of the gear21. This reduces the leverage between the worm and the worm gear, tosuch an extent that the gear is unable to rotate the worm, which resultsin a dead lock when the operation of the steering is reversed; That isto say, the steering wheel is prevented from rotating the steeringcolumn; while the steering column has a free leverage for rotating thesteering wheel. This is enlarged in the detail Fig. 2.

Having thus described my invention, what Iclaim and desire to secure byLettersPatent is p 1. In asteering mechanism for vehicles, thecombination with the vehicle frame embodying a horizontal guide having acircular vertical wall with an'inwardly projecting circular track flangeat the top having "its track face directed downwardly, a turntable ringlocated Within the circular guide below the track flange, anti-frictionrollers interposed between the said ring and flange and between the saidring and lower portion of the guide, a vertical steering wheel, locatedwithin the ring, bearings in which the steering wheel is j ournaledlocated below and supporting the ring and guide, a segmental rack rigidwith the ring and located below the guide, a pinion journaled in theframe and meshing with the rack and a wheel for rotating the pinion.

2. In a vehicle steering mechanism, the combination with the vehicleframe embodying a horizontal guide having a circular vertical wall withan inwardly projecting circular track flange at the top having its trackface directed downwardly, a turntable ring located within the circularguide below the track flange, anti-friction rollers interposed betweenthe ring and track face of the flange and between the guide and outerface of the ring near the bottom thereof, two parallel chords rigid withand extending below the turntable ring, bearing boxes movable verticallyin said chords, a vertical steering wheel journaled in said boxes, asegmental rack rigid with the turntable ring and located below the sameand above the axis of the steering wheel, a pinion journaled on a fixedaxis and meshing with the rack, and means for turning the pinion tosteer the vehicle.

3. In. a vehicle steering mechanism, the combination with the vehicleframe embodying a horizontal guide having a circular vertical wall withan inwardly projecting annular track flange at the top having its trackface directed downwardly, a turntable ring located within the circularguide below the track flange, antifriction rollers interposed betweenthe ring and track face of the flange and between the guide and outerface of the ring near the bottom thereof, oppositely disposed clipsrigid with the turntable ring and having their upper ends 7 extendedover the track flange, a steering wheel journaled on a horizontal axisand located within the turntable ring,and means for turning saidturntable ring andwheel horizontally with relation to the guide andvehicle frame, substantially as described.

In testimonywhereof I'have hereunto set my hand in the presence of twosubscribing witnesses.

BENJAMIN HOLT. Witnesses GEORGE CoWnLL, R. E. MANN.

